Spectracide Weed & Grass Killer Concentrate is a non-selective herbicide formulated for spot treatment of weeds and grasses. This 40 fl oz concentrate makes up to 13 gallons. It provides visible results in three hours by killing the root. For best results, apply this product when temperature is above 60° F. Protect desirable plants with a piece of cardboard or plastic and apply when air is calm to avoid drift to desirable plants. This product is ideal for use on patios, walkways and driveways; around flowers, shrubs and trees; along fences and foundations; and in large areas.